class Bird:

    def isWing(self):
        print("鸟有翅膀")


    def fly(self):
        print("鸟会飞")


class Ostrich(Bird):
    # 重写
    def fly(self):
        print("鸵鸟不会飞")



ostrich = Ostrich()
ostrich.fly()
Bird.fly(ostrich)
